Puretane’s premium butane is triple refined through fractional distillation and then filtered 9 times for maximum purity. Puretane doesn’t stop there, to preserve the highest purity of the butane gas, Puretane N-Butane is packaged in food grade aluminum cans. These aluminum cans have a BPA-free plastic lining that protects the gas from contamination, such as corrosion and the toxic manufacturing lubricants typically found in conventional steel butane cans. Puretane’s aluminum cans are also recyclable, simply puncture the empty can and toss it in your recycling bin along with your soda pop cans.